Where is a good place to get Modal Filter Frequency Recipes?

Question

The ModalFilter Sound is excellent and all depends on the values in its ModeAmps and ModeFreqs parameters. The secret recipes.

I suppose I could go around recording myself smacking things with a hammer and looking at the frequency analysis. But is there a good place to find modal filter frequency recipes?

Comments

I found the top edge of the display in the Spectrum Editor, focussing on a narrow slice to get frequencies and amps info was very useful.

Answer 1

Look what my friend Tom found:

a list of modal filter frequency recipes in the CSound manual

eg.

Dahina tabla [1, 2.89, 4.95, 6.99, 8.01, 9.02]
...

 

Answer 2

Very nice! Thank you, Alan!
I can give you another source for such modal frequencies / ratios: NEL has built a modal synthesizer called SCI PHY ADDITIVE MODAL SYNTHESISER. It contains a sound that can extract the modal frequencies /ratios from Kymas spectral files. The cool thing is that you can move through the whole Spectralfile using TimeIndex. This means that different modal frequencies/relations can be obtained at different positions in the file.

 

Comments

That's very interesting!

How is a "mode" different from what's in a Spectral analysis?

Gustav / Cristian - the sound samples on the Sci Phy page don't seem to work.

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IMO I dont think there is much difference at all, except that a spectral analysis has a time axis and that I dont think there is an equivalent to 'nodes' which are the opposite of modes. Nodes being frequencies that are dampened rather than resonating.   

I notice the CSound manual link lists only frequencies and not amplitides which I think is a bit of an ommission - plugging these freqs (or ratios) straight into a modal filter or synthetic spectrum without the natural roll-off you get in higher harmonics will produce some nasty sounding results unless you approximate that same roll-off. To my mind the amps are just as important information as the freqs.

That's where spectral analysis shines IMO, you can pick your point or segment in time (perhaps even perform an averaging of freqs and amps for a small segment) and then hover over an individual track to see freq and amp data

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Oh, a little time has passed here...
I'll try to explain the whole thing:
From the Spectrum Tracks a desired number of louder frequencies are selected. Their ratios, which are calculated from the single frequencies and the fundamental ones, are then output together with the corresponding levels.